The present invention relates generally to asynchronous transfer mode (ATM) communications systems, and more specifically to a lock control mechanism for a multiprocessor system.
It is known to transport ATM cells between source and destination nodes via intermediate node using two ring transmission lines, one for each direction of transmission. To ensure against possible cable failures, the transmission system is duplicated for each direction of transmission. On encountering a fault in the active line, the system is automatically switched to the spare line to minimize system downtime. However, this mode of transmission is not cost effective. It is also known to transport ATM cells on two ring transmission lines without duplicating the lines. In the event of a fault, the network node on each end of the faulty ring section establishes a folded connection so that source and destination nodes are interconnected by a single ring transmission line for each direction of transmission. However, for routing the cells through the reconfigured network it takes a substantial amount of time, thus resulting in a long recovery time.